Journal Madagascar Conservation - Madagascar Wildlife ...

MADAGASCAR CONSERVATION & DEVELOPMENT VOLUME 3 | ISSUE 1 — DECEMBER 2008 PAGE 45
the adjacent Montagne d’Ambre National Park (e.g. Station des
Roussettes, mean 2,378 mm). As a result the vegetation of the
Forêt d’Ambre is distinctly mesic and has been described as
transitional between lowland rainforest (at higher elevations)
and dry deciduous western forest (at lower elevations) (White
1983, Raxworthy and Nussbaum 1994). Due to its close proximity
to the town of Antsiranana and other large communes such
as Sakaramy and Joffreville, the forest is also characterized by
semi - disturbed and heavily degraded areas of anthropogenically
altered habitat.
The partial isolation of the low altitude dry deciduous
forest of this site from the five other major localized areas
of dry deciduous forest (Analamera, Ankarana, Daraina,
Montagne des Français and Orangea) located in the extreme
north of Madagascar is believed to be as a result of human
settlement [estimated at approximately 1,500 - 2,000 years
ago (Hurles et al. 2005)] and subsequent anthropogenic
deforestation (Vallan 2000, Vallan 2002, D’Cruze et al. 2006).
However, it is important to note that the sub - arid habitats
which separate the rainforest within the Montagne d’Ambre
complex from the rest of the major eastern rainforest block do
not appear to have been created by the same recent human
activity (Raxworthy and Nussbaum 1994). As the Montagne
d’Ambre mountain complex is volcanic in origin, composed
of basaltic rock formed about 14 million years ago (Du Puy
and Moat 1996), it probably received more continuous precipitation
during dry periods to support a forest cover which
may have been partially isolated for millions of years from
other northern and eastern forest blocks (Raxworthy and
Nussbaum 1994).
The Forêt d’Ambre Special Reserve with a surface area
of 4,810 ha (S12°20’ - S12°30’, E49°09’ - E49°14’) was formally
created in 1958. This IUCN Category II protected area includes
forest between 150 and 1,143 m a.s.l. and is characterized by
numerous high - standing hills, ridges and plateaus interspersed
with valleys, channels and gullies. Several rivers and streams
flow through the Reserve and a permanent body of water known
locally as Lac Mahery can be found at 343 m a.s.l. Further protection
is provided to forest in this mountain range by the adjacent
Montagne d’Ambre National Park (18,200 ha) which was also
created in 1958. Both the Forêt d’Ambre Special Reserve and
the Montagne d’Ambre National Park are currently managed
by ANGAP (‘Association Nationale pour la Gestion des Aires
Protégées’). In addition, a small privately owned and managed
area of forest known as the ‘Fontenay Nature Park’ borders both
of these protected areas.
Madagascar is blessed with a rich herpetofauna comprising
over 600 species of reptiles and amphibians, more than
95 % of which are endemic to the Malagasy region (Glaw and
Vences 2007). Based on specific combinations of climate,
topography and vegetation, Madagascar has been traditionally
divided into five or six biogeographic zones (Cornet 1974,
Schatz 2000), More recently, Wilmé et al. (2006) divided the
island into 10 areas of endemism according to the main
watersheds and species distribution data. Among these, the
areas characterized by humid rainforest (predominantly the
east of the island) have attracted most of the attention from
researchers because of their high biodiversity and advanced
conservation needs. However, fieldwork conducted in recent
years has begun to reveal the extraordinary importance of
the extreme north as a biological center of herpetological
diversity and endemism, which has included the discovery of a
multitude of undescribed herpetological taxa (Raxworthy and
Nussbaum 1994, Mori et al. 2006, D’Cruze et al. 2006, 2007,
Rakotondravony 2006).
Despite the relatively old age of the Special Reserve and the
interesting biogeographic history of the site, prior to this study
virtually nothing was known about its herpetofauna. Specimens
had been collected from the Montagne d’Ambre complex for
more than 100 years, with the earliest herpetological collection
(deposited in the Musée National d’Histoire Naturelle,
Paris) made by Alluaud and Belly in 1893 (Mocquard 1895).
Typically, however these specimens lack precise locality data,
which is a significant problem because of the wide elevational
range and diverse array of habitat types in the region. Species
were often represented by a single specimen, which made it
impossible to understand character variation within local populations
and increased the risk of taxonomic errors. As a result no
comprehensive species list for the amphibians and reptiles of
the Forêt d’Ambre Special Reserve has ever been published.
In contrast several vertebrate species lists have been
produced for the adjacent Montagne d’Ambre National Park
(IUCN / UNEP / WWF 1987, Nicoll and Langrand 1989, Andreone
1991, Raxworthy and Nussbaum 1994). However, even the
most recent survey conducted by Raxworthy and Nussbaum
(1994) was done over a decade ago and is in need of
revision in order to keep up with new discoveries and
taxonomic progress.
Given the lack of published information regarding this
important site of conservation, we conducted a rapid survey
of amphibians and reptiles in order to (1) update the existing
knowledge regarding the composition, geographical and
ecological distribution of the herpetofauna of the Forêt d’Ambre
Special Reserve, (2) highlight the herpetological diversity of
this area and identify the current threats to its conservation,
(3) review the existing conservation initiatives and (4) provide
recommendations that will facilitate the development of an
effective and sustainable management plan for the reserve.
We also take the opportunity to provide a preliminary species
list for the Fontenay Nature Park and an updated species list
for the Montagne d’Ambre National Park.
STUDY SITES Field work was centered at two camps
situated along the road which runs along the eastern edge
of the Reserve from Sakaramy to Joffreville, which facilitated
exploration of the full altitudinal range found within the Forêt
d’Ambre Special Reserve and adjacent unprotected areas
(150 - 1,143 m). Camp 1, Hotely Tsara ‘Lasopy’ Antanambetsara,
S12º27.98’, E49º 13.82’, 454 m altitude, adjacent to low
altitude rainforest, was occupied from 18 to 25 February 2008.
Camp 2, Le Domaine de Fontenay, S12º 29.70’, E49º12.15’, 720
m altitude, also adjacent to low altitude rainforest, was occupied
from 25 to 29 February 2008. In addition, short excursions
were carried out by a second team in the Fontenay Nature
Park (S12º29.70’, E49º12.15’, between 19 and 28 February
2008) and to the Lac Mahery (27 February 2008). An initial
excursion to Forêt d’Ambre was carried out on 12 March 2007.
Fieldwork in Montagne d’Ambre National Park was carried out
by many different research teams during several excursions
between 1994 and 2008 and most of the results are summarized
in Glaw and Vences (2007).